I'll admit I wasn't being serious last night, and I appear to have accidentally steered this thread more into the direction of spelling rather than history.
I'd like to get back to a slightly more rigorous examination of the history of Sea Shanties. To my mind, this doesn't involve people fighting with "facts" but rather using a working hypothesis and trying to find counter examples which take the argument further. If we can take your facts as working hypotheses from this point of view, we may make some progress. Is this OK?